// Copyright 2022 The CubeFS Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
// implied. See the License for the specific language governing
// permissions and limitations under the License.

package fileutil

import (
	"errors"
	"os"
)

var (
	ErrLocked     = errors.New("fileutil: file already locked")
	ErrNotSupport = errors.New("fileutil: not support")
)

type Locker struct{ *os.File }

func openLockFile(filename string) (*os.File, error) {
	f, err := os.OpenFile(filename, os.O_CREATE|os.O_RDONLY, 0o600)
	if err != nil {
		return nil, err
	}
	return f, nil
}

func TryLockFile(path string) (*Locker, error) {
	return flockTryLockFile(path)
}

func LockFile(path string) (*Locker, error) {
	return flockLockFile(path)
}

func (l *Locker) Unlock() error {
	return l.Close()
}
